tert-Butyl (2-(2-(2-(2-(4-(6-methyl-1,2,4,5-tetrazin-3-yl)phenoxy)ethoxy)ethoxy)ethoxy)ethyl)carbamate

This PROTAC linker is a Boc-protected, poly(ether) scaffold designed to provide conformational flexibility and efficient spatial separation between ligand domains. Its ether-rich framework supports favorable linker dynamics that can improve ternary complex formation and targeted protein degradation performance in PROTAC workflows. The following sections describe the structure and practical reactivity considerations for constructing PROTAC conjugates using this linker.

Structure: The molecule is a tert-butyl carbamate (Boc-protected amine) connected through an ethylene-oxy rich, flexible polyether chain to an aromatic phenoxyethoxy motif. It contains carbamate and ether linkages, an aromatic ring, and a tetrazine heteroaromatic core suitable for bioorthogonal chemistry.

Reactivity: For PROTAC assembly, Boc-protected amines are typically handled via controlled deprotection under mild acid conditions to reveal the reactive amine for subsequent coupling. The tetrazine functionality is commonly exploited in inverse-electron-demand Diels–Alder ligation with strained dienes, enabling rapid conjugation under aqueous-compatible conditions. Standard peptide/amide coupling strategies can be used after amine unveiling, with appropriate bases and coupling reagents in polar organic solvents.